After the recently exposed hoax that had fans convinced that Fallout 4 was in the works, it might be preferable to treat the following report with caution, but according to leaked casting documents it looks like a sequel from Bethesda is in the works.
The documents, obtained by Kotaku, suggest a Boston setting for the next game in the series, and introduce a couple of characters that may or may not make it into the final game.
The casting script kicks off with the traditional "War. War never changes." quote (interestingly, voiced by the player character and not Ron Perlman in this instance), and introduces a character called Preston Garvey who sends the player on a mission to salvage a fusion core from a museum in the Commonwealth (which represents what's left of Massachusetts).
The report in Kotaku also mentions two other characters, a DJ named Travis Miles and an engineer called Sturges (the latter of which is described in the article as "a cross between Buddy Holly and Vin Diesel"). Other details in the documents include a mission set in the Institute, Fallout's vision of MIT.
The details included in the report, and the setting described on the casting documents, certainly sounds authentic. There's still no official word from Bethesda on the subject, so keep that in mind before you get too excited, but the signs are good that Fallout 4 is in development. We're keeping our fingers crossed that's for sure.